Lots of Monday morning quarterbacks in this thread. We are talking about children. You want a group of untrained teenagers to charge an active shooter? Really?
Untrained is the operative word here.
+1 Untrained. And unequipped. It takes trained and properly equipped professionals to effectively go up against a determined shooter using a semi-auto (or auto) rifle. Look what happened when the LA Police, only armed with side arms, went up against 2 determined shooters at the Bank of America shoot-out in LA in 1997.
http://en.wikipedia.org/wiki/North_Hollywood_shootoutThe LA police are no pushovers. Two guys did it to them. Unarmed untrained teenagers? No way. Run and hide was the only option; not a good one, but the only one.